It is expected to have some clock energy at 2fdac. The DAC core architecture utilizes both rising and falling edges of the DAC clock. Part of the circuitry is running at twice the DAC sample rate. Similar power level can be observed at the DAC output if there is no low pass filtering.

This is an inherent frequency content in the AD9779A regardless of the DAC PLL status. If RF emission is a problem in your application, you may want to consider some RF shielding and absorbing measures.

It is expected to have some clock energy at 2fdac. The DAC core architecture utilizes both rising and falling edges of the DAC clock. Part of the circuitry is running at twice the DAC sample rate. Similar power level can be observed at the DAC output if there is no low pass filtering.

This is an inherent frequency content in the AD9779A regardless of the DAC PLL status. If RF emission is a problem in your application, you may want to consider some RF shielding and absorbing measures.